Tools and Precautions
To take apart your Xbox, you will need a Torx 10 and a Torx 15 screwedriver. If you don't have the proper tools for the job, you run the risk of stripping the console's screws. This will make it difficult to put the unit back together.
When taking apart your console, make sure it is powered off and unplugged. Wear protective gloves to reduce the risk of getting shocked, and be sure to keep track of the screws you remove and where all of the pieces of the console go. This will make reassembly easier.
Lay out a towel and use it as your work surface--screws won't bounce and get lost should you drop one. Storing the screws in a cup or bowl will help prevent them from getting lost.
Remove the Outer Shell
Remove the four rubber pads that cover the screws on the bottom of the console. Two stickers also must be removed. Afterward, unscrew all six screws with your T15 screwdriver. Flip the console right-side-up and remove the cover.
Remove the Components
Remove the grey ribbon cable connected to the DVD drive, the yellow power cable connected to the DVD drive and the hard drive's power cable. As you take apart your console, be sure to keep track of what you're doing and be careful, as the internal components can be delicate and should be handled with care.
There are three screws inside the console that hold the hard drive and DVD drive in place. Remove the screws and the drives to access the motherboard. Take out the yellow power cable and cooling fan as well as the main power cable.
When you take out the cable for the front panel and the controller port, you have 11 more screws to remove. After taking them out, you can remove the motherboard.